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Efficacy and safety of lowering LDL cholesterol in older patients: a systematic review and meta-analysis of randomised controlled trials

Author/s: 
Gencer, Baris, Marston, Nicholas A., Im, KyungAh, Cannon, Christopher P., Sever, Peter, Keech, Anthony, Braunwald, Eugene, Giugliano, Robert P., Sabatine, Marc S.

Background: The clinical benefit of LDL cholesterol lowering treatment in older patients remains debated. We aimed to summarise the evidence of LDL cholesterol lowering therapies in older patients.

Methods: In this systematic review and meta-analysis, we searched MEDLINE and Embase for articles published between March 1, 2015, and Aug 14, 2020, without any language restrictions. We included randomised controlled trials of cardiovascular outcomes of an LDL cholesterol-lowering drug recommended by the 2018 American College of Cardiology and American Heart Association guidelines, with a median follow-up of at least 2 years and data on older patients (aged ≥75 years). We excluded trials that exclusively enrolled participants with heart failure or on dialysis because guidelines do not recommend lipid-lowering therapy in such patients who do not have another indication. We extracted data for older patients using a standardised data form for aggregated study-level data. We meta-analysed the risk ratio (RR) for major vascular events (a composite of cardiovascular death, myocardial infarction or other acute coronary syndrome, stroke, or coronary revascularisation) per 1 mmol/L reduction in LDL cholesterol.

Findings: Data from six articles were included in the systematic review and meta-analysis, which included 24 trials from the Cholesterol Treatment Trialists' Collaboration meta-analysis plus five individual trials. Among 244 090 patients from 29 trials, 21 492 (8·8%) were aged at least 75 years, of whom 11 750 (54·7%) were from statin trials, 6209 (28·9%) from ezetimibe trials, and 3533 (16·4%) from PCSK9 inhibitor trials. Median follow-up ranged from 2·2 years to 6·0 years. LDL cholesterol lowering significantly reduced the risk of major vascular events (n=3519) in older patients by 26% per 1 mmol/L reduction in LDL cholesterol (RR 0·74 [95% CI 0·61-0·89]; p=0·0019), with no statistically significant difference with the risk reduction in patients younger than 75 years (0·85 [0·78-0·92]; pinteraction=0·37). Among older patients, RRs were not statistically different for statin (0·82 [0·73-0·91]) and non-statin treatment (0·67 [0·47-0·95]; pinteraction=0·64). The benefit of LDL cholesterol lowering in older patients was observed for each component of the composite, including cardiovascular death (0·85 [0·74-0·98]), myocardial infarction (0·80 [0·71-0·90]), stroke (0·73 [0·61-0·87]), and coronary revascularisation (0·80 [0·66-0·96]).

Interpretation: In patients aged 75 years and older, lipid lowering was as effective in reducing cardiovascular events as it was in patients younger than 75 years. These results should strengthen guideline recommendations for the use of lipid-lowering therapies, including non-statin treatment, in older patients.

Keywords 
Cardiovascular Diseases Clinical Protocols cholesterol

Effects of weight loss during a very low carbohydrate diet on specific adipose tissue depots and insulin sensitivity in older adults with obesity: a randomized clinical trial

Author/s: 
Gower, Babara, Goss, Amy, Soleymani, Taraneh, Stewart , Mariah, Pendergrass, May, Lockhart, Mark, Kranz, Olivia, Dowla, Shima, Bush, Nikki, Barry, Valene Garr, Fontaine, Kevin R.

Background: Insulin resistance and accumulation of visceral adipose tissue (VAT) and intermuscular adipose tissue (IMAT) place aging adults with obesity at high risk of cardio-metabolic disease. A very low carbohydrate diet (VLCD) may be a means of promoting fat loss from the visceral cavity and skeletal muscle, without compromising lean mass, and improve insulin sensitivity in aging adults with obesity.

Objective: To determine if a VLCD promotes a greater loss of fat (total, visceral and intermuscular), preserves lean mass, and improves insulin sensitivity compared to a standard CHO-based/low-fat diet (LFD) in older adults with obesity.

Design: Thirty-four men and women aged 60-75 years with obesity (body mass index [BMI] 30-40 kg/m2) were randomized to a diet prescription of either a VLCD (< 10:25:> 65% energy from CHO:protein:fat) or LFD diet (55:25:20) for 8 weeks. Body composition by dual-energy X-ray absorptiometry (DXA), fat distribution by magnetic resonance imaging (MRI), insulin sensitivity by euglycemic hyperinsulinemic clamp, and lipids by a fasting blood draw were assessed at baseline and after the intervention.

Results: Participants lost an average of 9.7 and 2.0% in total fat following the VLCD and LFD, respectively (p < 0.01). The VLCD group experienced ~ 3-fold greater loss in VAT compared to the LFD group (- 22.8% vs - 1.0%, p < 0.001) and a greater decrease in thigh-IMAT (- 24.4% vs - 1.0%, p < 0.01). The VLCD group also had significantly greater thigh skeletal muscle (SM) at 8 weeks following adjustment for change in total fat mass. Finally, the VLCD had greater increases in insulin sensitivity and HDL-C and decreases in fasting insulin and triglycerides compared to the LFD group.

Conclusions: Weight loss resulting from consumption of a diet lower in CHO and higher in fat may be beneficial for older adults with obesity by depleting adipose tissue depots most strongly implicated in poor metabolic and functional outcomes and by improving insulin sensitivity and the lipid profile.

Trial registration: NCT02760641. Registered 03 May 2016 - Retrospectively registered.

© The Author(s) 2020.

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